Ghastly plaster spread over cottage initially (8)
I believe the answer is:
spectral
'ghastly' is the definition.
(I've seen this before)
'plaster spread over cottage initially' is the wordplay.
'spread' is an anagram indicator.
'over' indicates putting letters inside.
'initially' suggests taking the first letters.
The first letter of 'cottage' is 'c'.
'plaster' anagrammed gives 'spetral'.
'spetral' enclosing 'c' is 'SPECTRAL'.
(Other definitions for spectral that I've seen before include "Like a colourful band" , "Rap Celts for being ghostly" , "Ghastly" , "covering a range of colours" , "Spooky" .)